1. Field of the Invention
The present invention relates to thin film EL (electroluminescence) panels, and in particular to filter-mode thin film EL panels comprising a combination of a thin film EL panel and a color filter.
2. Description of the Related Art
Recently, a filter-mode thin film EL panel comprising a thin film EL element and a color filter, both of which are oppositely disposed to each other, has been developed so as to provide a multi-color thin film EL panel. A filter-mode is such a mode that a single-color light exiting from the thin film EL element is distributed by a color filter comprising a plural color organic material to provide a plurality of luminescent colors. Since a single-color luminescent layer may be formed on the EL element in the filter-mode thin film EL panel, it is possible to simplify the production process. However, a gap between the EL element and the color filter causes a viewing angle dependency (the so-called color unevenness). Thus, the thin film EL panel has hitherto been formed in such a manner that both the EL element and the color filter are placed as close as possible without placing anything therebetween.
However, because the above-described conventional thin film EL panel is formed in such a manner that the EL element and the color filter come close, the EL element and the color filter may be brought into contact together to create scratches when the color filter is aligned with the pixel in its manufacturing step.
Also, because the EL element has such a feature that it is repeatedly expanded and contracted in the width direction during its operation (in an alternating current driving mode), the EL element is partially brought into contact with the color filter in the production step, thereby creating pixel defects due to dielectric breakdown and linear defects due to the breakage of the electrodes.
For that reason, the present applicant has proposed in Japanese Laid-open Publication No. 5-94879 a method for forming a spacer having a light shading property and projected at about a right angle to the surface of a substrate between the adjacent pixels of the above-described EL element.
However, the spacer according to the technology of the above-described patent publication is a resin-type spacer obtained by forming a resin on the entire surface of the EL element by a rotational coating method, and thereafter leaving only a portion of the resin formed between the adjacent pixels of the EL element by photolithography, etc. Therefore, its production process is complicated due to the increased number of steps. Consequently, the thin film EL panel according to the technology of the above-described patent publication is not satisfactory due to its complicated production process, and the process for producing this thin film EL panel is not the optimum process.